<?php
/**
 * @author anderyly
 * @email admin@aaayun.cc
 * @link http://vclove.cn/
 * @copyright Copyright (c) 2020
 */

function gmt_iso8601($time)
{
    $dtStr = date("c", $time);
    $mydatetime = new DateTime($dtStr);
    $expiration = $mydatetime->format(DateTime::ISO8601);
    $pos = strpos($expiration, '+');
    $expiration = substr($expiration, 0, $pos);
    return $expiration . "Z";
}

$id = '';
$key = '';
$bucket = '';
$domain = '';

$dir = 'qrcode';

$now = time();
$expire = 100;  //设置该policy超时时间是10s. 即这个policy过了这个有效时间，将不能访问。
$end = $now + $expire;
$expiration = gmt_iso8601($end);


//最大文件大小.用户可以自己设置
$condition = array(0 => 'content-length-range', 1 => 0, 2 => 1048576000);
$conditions[] = $condition;

// 表示用户上传的数据，必须是以$dir开始，不然上传会失败，这一步不是必须项，只是为了安全起见，防止用户通过policy上传到别人的目录。
$start = array(0 => 'starts-with', 1 => '$key', 2 => $dir);
$conditions[] = $start;

$arr = array('expiration' => $expiration, 'conditions' => $conditions);
$policy = json_encode($arr);
$base64_policy = base64_encode($policy);
$string_to_sign = $base64_policy;
$signature = base64_encode(hash_hmac('sha1', $string_to_sign, $key, true));

$response = array();
$response['accessid'] = $id;
$response['host'] = $domain;
$response['policy'] = $base64_policy;
$response['signature'] = $signature;
$response['expire'] = $end;
$arr = [
    'code' => 0,
    'success' => true,
    'msg' => '签名成功',
    'data' => $response
];
echo json_encode($arr);
